This proposal addresses a need for an improved technology for early cancer detection and rapid screening. Recent advances in nanotechnology and high resolution imaging have led to the development of new investigative tools capable of probing biological tissues at the cellular level. These tools can be used to localize abnormal neoplastic cells and expedite the screening process. Physical Sciences Inc. (PSI), in collaboration with Northeastern University (NEU), proposes to develop a technology that could be used for screening of early stage epithelial pre-cancerous lesions. Enhanced-contrast high-resolution optical coherence tomography (OCT) imaging based on tumor targeted delivery of microparticles will be used to localize abnormal lesions within the tissue. Gold coated microparticles functionalized with epithelial cell specific targeting ligands will be evaluated in vitro and in vivo for specific binding to epithelial targets for early cancer diagnosis. In Phase I, this technology will be tested on various colon cancer cell lines in cultures and in an orthotopic human colon model in mice upon topical administration. The Phase I results and observations will be used to improve the technology in Phase II. A pilot clinical in vivo study on an animal model will be performed to test the effectiveness of this technology.